At this point i would wait for the NX announcement. Wii U prices will likely tumble at that point to clear. Therefore saving you money the hardware NX not be backwards compatible. Then if it is, you lots ofcontent from day 1 that want to play.

I'd wait for NX or for a price cut.

I doubt the NX will be BC with Wii U titles... Especially hardware based BC akin to the early PS3s(with PS2 games), Wii's(with Gamecube games) etc. It would increase the cost of production for each NX unit significantly and given Nintendo's poor state of affairs when it comes to their latest home console, the benefits(to them) of BC would be negated by the benefits of a lower production cost. Just my opinion.

Buy now, support Nintendo, and you will be the owner of rare unique console in the future, its a great console.

Don't forget that, unless the NX uses another GamePad-like controller (which is extremely unlikely), or unless Nintendo starts selling separate GamePads (which they haven't even done during the three years the Wii U was on the market), backwards compatibility is almost impossible with most Wii U games. You will also be missing out on most of the online experiences, as most people would've moved on to other games by then.

I'd say most Wii U games are just as functional with a regular controller or Wii remotes as they are the tablet.

GamePad is required for many games; Nintendo Land, Pikmin 3, Super Mario 3D World, Captain Toad, Kirby and the Rainbow Curse, Super Mario Maker, Splatoon, upcoming Star Fox Zero out of the top of my head. It's vital to most of the Wii U library, and don't suggest that Nintendo is going to patch all those games in some way or form. 

It's a huge exageration to say it's vital to most of the library, you've basically listed a few of the handful of games reliant on the pad. NSMB-U, Mario Kart 8, Smash Bros Brawl, Bayonetta 2, Donkey Kong Country: Tropical Freeze, Hyrule Warriors, The Wonderful 101, Wind Waker HD. There's 8 games just off the top of my head that someone may want a Wii U for that don't require the gamepad in the slightest.

Here's a list of Pro Controller compaible Wii U games:

https://en.wikipedia.org/wiki/List_of_Wii_U_games_that_use_the_Wii_U_Pro_Controller

Though I do note Pikmin 3, Super Mario 3D World and Kirby and the Rainbow Curse are all listed as supported (source being Nintendo e-shop) though I'm really not sure how Kirby would work without the pad.

Don't get me wrong, I love the game pad, I just don't think removing it is going to be much of an issue for any future backwards compatability simply because barely any Wii U games truly utilise it.

It's barely cheaper than a PS4, it's a rip off.

Thats your opinion, if your a Nintendo fan and like there games its more than worth it, to me the PS4 is a rip off, im sure you would say to me thats your opinion.